Neutrinos and cosmological matter–antimatter asymmetry: A minimal seesaw with Frampton–Glashow–Yanagida ansatz

2017 ◽  
Vol 32 (16) ◽  
pp. 1742004
Author(s):  
Jue Zhang ◽  
Shun Zhou

In light of the latest neutrino data, we revisit a minimal seesaw model with the Frampton–Glashow–Yanagida ansatz. Renormalization-group running effects on neutrino masses and flavor mixing parameters are discussed and found to essentially have no impact on testing such a minimal scenario in low-energy neutrino experiments. However, since renormalization-group running can modify neutrino mixing parameters at high energies, it does affect the leptogenesis mechanism, which is responsible for the observed matter–antimatter asymmetry in our Universe. Furthermore, to ease the conflict between the naturalness argument and the successful leptogenesis, a special regime for resonant leptogenesis is also emphasized.

Author(s):  
V V Vien ◽  
H N Long ◽  
A E Cárcamo Hernández

Abstract We construct a low-scale seesaw model to generate the masses of active neutrinos based on $S_4$ flavor symmetry supplemented by the $Z_2 \times Z_3 \times Z_4 \times Z_{14}\times U(1)_L$ group, capable of reproducing the low-energy Standard Model (SM) fermion flavor data. The masses of the SM fermions and the fermionic mixing parameters are generated from a Froggatt–Nielsen mechanism after spontaneous breaking of the $S_4\times Z_2 \times Z_3 \times Z_4 \times Z_{14}\times U(1)_L$ group. The obtained values for the physical observables of the quark and lepton sectors are in good agreement with the most recent experimental data. The leptonic Dirac CP-violating phase $\delta _\mathrm{CP}$ is predicted to be $259.579^\circ$ and the predictions for the absolute neutrino masses in the model can also saturate the recent constraints.


2010 ◽  
Vol 25 (23) ◽  
pp. 4339-4384 ◽  
Author(s):  
SHAMAYITA RAY

We consider different extensions of the Standard Model which can give rise to the small active neutrino masses through seesaw mechanisms, and their mixing. These tiny neutrino masses are generated at some high energy scale by the heavy seesaw fields which then get sequentially decoupled to give an effective dimension-5 operator at the low energy. The renormalization group evolution of the masses and the mixing parameters of the three active neutrinos in the high energy as well as the low energy effective theory is reviewed in this paper.


2003 ◽  
Vol 18 (22) ◽  
pp. 3909-3920
Author(s):  
K. WHISNANT

Current constraints on neutrino mass and mixing parameters are briefly reviewed, and the prospects for future measurements in long-baseline neutrino experiments are discussed. Parameter degeneracies are a generic problem in the three–neutrino analysis of long-baseline neutrino appearance measurements, and can lead to different inferred values for the neutrino mixing angle θ13 and often mix CP violating and CP conserving solutions. Possible experimental strategies for reducing or eliminating such degeneracies and/or the CP confusion are discussed.


2007 ◽  
Vol 22 (18) ◽  
pp. 1341-1347 ◽  
Author(s):  
HE ZHANG

Assuming the existence of one light sterile neutrino, we investigate the neutrino flavor mixing matrix in matter. Sum rules between the mixing parameters in vacuum and their counterparts in matter are derived. By using these new sum rules, we obtain the simple but exact expressions of the effective flavor mixing matrix in matter in terms of neutrino masses and the mixing parameters in vacuum. The rephasing invariants, sides of unitarity quadrangles and oscillation probabilities in matter are also achieved. Our model-independent results will be very helpful for analyzing flavor mixing and CP violation in the future long-baseline neutrino oscillation experiments.


2010 ◽  
Vol 25 (11n12) ◽  
pp. 1014-1025 ◽  
Author(s):  
CHIAN-SHU CHEN

We investigate the possibility of thermal leptogenesis under the framework of radiative seesaw model with A4×Z2×Z4 leptonic flavour symmetry that leads to the tribimaximal mixing in neutrino sector. A five-dimensional effective Yukawa interaction with cutoff scale Λ which provides the deviations from tribimaximal mixing. Both A4 × Z4 and CP symmetries are spontaneously broken after the invented scalars generating VEVs. We consider the low-energy neutrino mixing angles to constrain the parameters in our model within three possible light neutrino spectrum in 1σ. We study the flavored effects on thermal leptogenesis in each scenario.


2007 ◽  
Vol 16 (01) ◽  
pp. 1-50 ◽  
Author(s):  
WAN-LEI GUO ◽  
ZHI-ZHONG XING ◽  
SHUN ZHOU

We present a review of neutrino phenomenology in the minimal seesaw model (MSM), an economical and intriguing extension of the Standard Model with only two heavy right-handed Majorana neutrinos. Given current neutrino oscillation data, the MSM can predict the neutrino mass spectrum and constrain the effective masses of the tritium beta decay and the neutrinoless double-beta decay. We outline five distinct schemes to parameterize the neutrino Yukawa-coupling matrix of the MSM. The lepton flavor mixing and baryogenesis via leptogenesis are investigated in some detail by taking account of possible texture zeros of the Dirac neutrino mass matrix. We derive an upper bound on the CP-violating asymmetry in the decay of the lighter right-handed Majorana neutrino. The effects of the renormalization-group evolution on the neutrino mixing parameters are analyzed, and the correlation between the CP-violating phenomena at low and high energies is highlighted. We show that the observed matter-antimatter asymmetry of the Universe can naturally be interpreted through the resonant leptogenesis mechanism at the TeV scale. The lepton-flavor-violating rare decays, such as μ→e+γ, are also discussed in the supersymmetric extension of the MSM.


2020 ◽  
Vol 35 (01) ◽  
pp. 2050004
Author(s):  
Guo-Yuan Huang ◽  
Noboru Sasao ◽  
Zhi-Zhong Xing ◽  
Motohiko Yoshimura

Unitarity of the [Formula: see text] lepton flavor mixing matrix [Formula: see text] is unavoidably violated in a seesaw mechanism if its new heavy degrees of freedom are slightly mixed with the active neutrino flavors. We propose to use the atomic transition process [Formula: see text] (for [Formula: see text], [Formula: see text]), where [Formula: see text] and [Formula: see text] stand, respectively for the excited and ground levels of an atomic system, to probe or constrain the unitarity-violating effects of [Formula: see text]. We find that the photon spectrum of this transition will be distorted by the effects of [Formula: see text] and [Formula: see text] as compared with the [Formula: see text] case. We locate certain frequencies in the photon spectrum to minimize the degeneracy of effects of the unitarity violation and uncertainties of the flavor mixing parameters themselves. The requirements of a nominal experimental setup to test the unitarity of [Formula: see text] are briefly discussed.


2004 ◽  
Vol 19 (08) ◽  
pp. 1167-1179 ◽  
Author(s):  
A. BELLERIVE

This paper reviews the constraints on the solar neutrino mixing parameters with data collected by the Homestake, SAGE, GALLEX, Kamiokande, SuperKamiokande, and SNO experiments. An emphasis will be given to the global solar neutrino analyses in terms of matter-enhanced oscillation of two active flavors. The results to-date, including both solar model dependent and independent measurements, indicate that electron neutrinos are changing to other active types on route to the Earth from the Sun. The total flux of solar neutrinos is found to be in very good agreement with solar model calculations. Future measurements will focus on greater accuracy for mixing parameters and on better sensitivity to low neutrino energies.


2005 ◽  
Vol 631 (1-2) ◽  
pp. 32-41 ◽  
Author(s):  
John Ellis ◽  
Andi Hektor ◽  
Mario Kadastik ◽  
Kristjan Kannike ◽  
Martti Raidal

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